T. rex overtakes Inner Harbor!

Dinosaur: 40-foot `Peck's Rex' is to be illuminated at night in window of the science center's new addition.

April 21, 2004|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

Back by popular demand after an absence of 65 million years, a 40-foot-long Tyrannosaurus rex has appeared this week at the south end of Baltimore's Inner Harbor promenade.

Dubbed "Peck's Rex," after the Fort Peck, Mont., region where the fossil skeleton was found, the dinosaur stands in the front window of the addition nearing completion at the Maryland Science Center.

Teeth gleaming and jaws agape, the T. rex is poised as if in the middle of a lunge at pedestrians on the promenade below. Plans call for the reptilian escapee from the late Cretaceous Period to be illuminated at night - a chilling new presence on the harbor's edge.

"He's going to be a big new part of Baltimore's skyline," said Roberta Cooks, director of exhibits at the science center.

Peck's Rex is the first of 14 dinosaur skeletons and skeleton casts to be mounted in the new Earth Science and Dinosaur Hall, the largest portion of the $35 million addition, which opens Memorial Day weekend.

Planners hope the dinosaurs will help boost attendance from the current 500,000 annual visitors to 800,000 in the first year after the opening.

Although the new tyrannosaur is an 800-pound foam and plastic replica, it is the first casting from the original ever put on display. It is a research-quality duplicate that is expected to attract paleontologists as well as visitors of all ages.

"This is as much detail as you can get in a fossil cast," said Chris Morrow, a preparator from Fort Peck Paleontology Inc., the nonprofit organization that excavated Peck's Rex and produced the $130,000 casting.

"From what I've seen from photographs, they do seem to be very good specimens and useful in the context of research," said Thomas R. Holtz Jr., a paleontologist and tyrannosaur expert at the University of Maryland, College Park. "I'm actually hoping to get out there this week."

The original Peck's Rex lived in the late Cretaceous Period, at the end of the Age of Dinosaurs 65 million years ago. It probably weighed 5 to 7 tons. Paleontologists disagree over whether its kind were primarily hunters or scavengers.

Morrow pointed out two faint impressions on the right side of Peck's Rex's upper jaw - divots that appear to have been caused by the teeth of another tyrannosaur. "It bit into the roots of the teeth," he said.

Evidence elsewhere in the animal's skull and jawbone suggest that the bite was followed by an infection, which might have caused its death.

"At the back of the right lower jaw, the hinge is all rotted out," Morrow said. "Whenever it went to move its jaw, it had to be extremely painful." There is no other clear evidence how it died.

Death left Peck's Rex in the sands of a shallow body of water, where its bones were buried in what became the hard sandstone of what geologists call the Hell's Creek formation.

It was discovered in 1997 by Lou Trembley, who worked on a dig led by paleontologist J. Keith Rigby Jr. of the University of Notre Dame. The original specimen is too fragile to display and is stored in a Montana vault. It is one of about two dozen T. rex skeletons ever found - and one of the most complete.

The remains recovered so far represent about 60 percent of the skeleton. Missing parts on Baltimore's replica - including most of its left rear leg - have been replaced by bone castings from other specimens.

As Baltimore's new tyrannosaur stands - or rather hangs from the ceiling of the new Dinosaur Hall - it displays bones rarely found at dig sites, or rarely displayed, said Marjit Goldberg, project manager of the dinosaur exhibit.

Most prominent are the gastralia, a basketlike section of the rib cage that some scientists believe assisted the reptiles in breathing. Found only in meat-eating dinosaurs, they are not ribs, and there is no counterpart in living vertebrates.

Although many gastralia bones have been found at other digs, this is believed to be the first time a fossil skeleton has been mounted with them.

And it was not entirely clear how it should be done.

"This is their interpretation of how it might have looked," Goldberg said. "We look forward to what other paleontologists are going to say about it."

Also present is the smile-shaped furcula between the dinosaur's breast bones. It's the equivalent of a turkey's wishbone and a clue to the evolutionary links between dinosaurs and birds.

Because it was found in context, Holtz said, the furcula will help curators of other collections identify those that may have been mistaken for gastralia bones.

Peck's Rex also has a rarely found third metacarpal - a vestigial and probably useless third finger on its left forelimb.

"It turns out third metacarpals have been kicking around in other collections and no one understood what they were," Holtz said.

Baltimore's display will offer Marylanders "a wonderful, close view of what dinosaur skeletons were like, and how we understand them," Holtz said.